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Biomedical subjects

Z Gibas

Publications and source records attributed to Z Gibas.

53 records · Page 3Linked to original sources
PubMed1984

A high-resolution study of chromosome changes in a human prostatic carcinoma cell line (LNCaP).

A high-resolution study of chromosomal rearrangements in a human prostatic cancer cell line, LNCaP, has been performed. The cytogenetic analysis revealed a pseudodiploid karyotype and the presence of seven marker chromosomes resulting from five aberrational events. The analysis of four clones derived from the original line showed a near-tetraploid chromosome number and the presence of the same seven markers observed in the original line. This is the first complete description of karyotypic rearrangements in a prostatic cancer cell line.

Cell Line↗
PubMed1984

Characterization of a transitional cell carcinoma line arising from a previously irradiated tumor.

A cell line derived from a poorly differentiated transitional cell carcinoma of the bladder in a patient previously treated with external beam radiation has been established. The line has stable hyperdiploid karyotype which is distinct from other established transitional cell carcinoma lines. Injection of the cells into nude mice induces tumor with histological characteristics similar to the original tumor. This line may serve as a model to study mechanisms of radioresistance in transitional cell carcinoma of the urinary bladder.

Aged↗
PubMed1984

Malignant teratoma of the testis with an isochromosome no. 12, i(12p), as the sole structural cytogenetic abnormality.

Cytogenetic analysis of a malignant teratoma of the testis revealed a hypotriploid karyotype with the presence of an isochromosome of the short arm of chromosome 12, i(12p), as the only structural abnormality. Most cells contained 3 copies of chromosome 12 and 2 copies of the i(12p) isochromosome. Thus, the genetic material located on the short arm of chromosome 12 was multiplied in the teratoma cells, being represented by 7 copies compared to 2 to 3 copies of other chromosomes. This finding confirms the reports that the i(12p) isochromosome is a specific chromosomal abnormality in cases of malignant testicular tumors.

Adult↗
PubMed1984

Chromosome changes in soft tissue sarcomas.

An analysis of chromosome aberrations in human tumors was performed in 29 cases of soft tissue sarcoma. The tumor tissues were disaggregated with collagenase and the cells cultured for 2-3 days. Analyzable metaphases were obtained in 15 cases, 4 of which showed only normal karyotypes. The remaining 11 tumors showed various numerical and structural abnormalities in their karyotypes: 8 tumors were near-diploid and the remaining 3 were near-triploid. G- and Q-banding analyses revealed clonal abnormalities in the 11 cases with the presence of marker chromosomes; 15 different chromosomes were involved in chromosome rearrangements, chromosomes 1 and 2 being the most frequently affected. Because of the heterogeneity of the tumor group investigated (neurogenic sarcoma, 2 liposarcomas, neurofibrosarcoma, synovial cell sarcoma, fibrosarcoma, mesothelioma, leiomyosarcoma, rhabdomyosarcoma, Ewing's sarcoma, and hemangiopericytoma), it was impossible to reach any conclusion on the specificity of the cytogenetic abnormalities for a particular tumor type.

Adult↗
PubMed1984

Nonrandom chromosomal changes in transitional cell carcinoma of the bladder.

Nine cases of transitional cell carcinoma (eight from the urinary bladder and one from the ureter; six noninvasive and three invasive) were subjected to detailed cytogenetic analysis with a G-banding method. The synchronization of primary cultures with methotrexate for high-resolution banding was performed in five cases. In the remaining four cases, the chromosomes were obtained from short-term cultures after prolonged (16 hr) exposure to Colcemid. Two cases were near-tetraploid, one was hypotriploid, and six were near-diploid (three hyperdiploid and three hypodiploid). All but one case showed various structural abnormalities in the karyotype. The chromosomal changes ranged from the presence of only two abnormal chromosomes (markers) to complex karyotypes with as many as 15 markers. In most tumors, the origin of the marker chromosomes could be readily deciphered. The nonrandom chromosomal aberrations included: (a) an isochrosome of the short arm of chromosome 5 (three cases); (b) monosomy of chromosome 9 found in four cases (this was the sole abnormality in one case); (c) involvement of chromosome 8 as an isochromosome of the long arm (two cases) or loss of the short arm due to deletion (one case) or translocation (one case); and (d) interstitial deletion of chromosome 13 (three cases). Our results indicate that the formation of i(5p) and monosomy 9 may be the primary karyotypic changes in two subgroups of transitional cell carcinoma. Involvement of chromosomes 8 and 13, on the other hand, seems to be a result of secondary karyotypic evolution. Two invasive tumors showed the presence of secondary clones, with additional structural chromosome aberrations superimposed on those already existing in the main cell population. In both cases, the additional aberrations involved the short arm of chromosome 11, resulting in loss of genetic material from the short arm. The short arm of chromosome 11, is the putative site of an oncogene which has been isolated from human bladder carcinoma cell lines. Deletion of the 11p was also seen in one case of noninvasive transitional cell carcinoma localized in the ureter; the material from 11p was probably translocated to chromosome 13. These findings suggest that the loss of genetic material from the short arm of chromosome 11 is a secondary event in the karyotypic evolution of transitional cell carcinoma, probably related to the invasive behavior of the tumor.

Aged↗
PubMed1983

Chromosome 6 in malignant melanoma.

Cytogenetic analysis of malignant melanoma (MM) cells from a number of cases revealed the frequent involvement of chromosome 6 in structural aberrations. The relevance of these findings to certain aspects of MM is briefly discussed.

Chromosome Aberrations↗
PubMed1983

Chromosomes and causation of human cancer and leukemia. LIII. Comprehensive cytogenetic analysis of an erythroleukemia.

A comprehensive cytogenetic analysis has been performed in a case of erythroleukemia (EL), M6 in the FAB classification. A bone marrow sample was shown to be characterized by an unusually high degree of polyploidy with the presence of a dominating hypotetraploid clone. G-banding analysis revealed extensive structural rearrangements involving chromosomes #1,#3,#12,#16,#17, and #21. The SCE frequency was higher in the cells of the dominant clone when compared to that of near-diploid, presumably nonmalignant cells. Cell cycle analysis revealed that the hypotetraploid cells progressed through the cell cycle much slower than did the near-diploid cells.

Aged↗
PubMed1983

Involvement of chromosomes 7 and 12 in large bowel cancer: trisomy 7 and 12q-.

Cytogenetic analysis of an adenocarcinoma of the large bowel with some villous features revealed consistent chromosome changes: trisomy of chromosomes No. 7, 12, and 20 and a deletion of part of the long arm of a chromosome No. 12. Examination of the chromosome findings in previously published cases of large bowel cancers and the data presented in this paper lead us to suggest that trisomy No. 7 and 12q- may be nonrandom (primary) karyotypic changes in a subgroup of large bowel cancers.

Adenocarcinoma↗
PubMed1983

Unusual SCD in cancer cells: a phenomenon related to decreased BrdU incorporation?

The simultaneous presence of chromosome segments with and without sister chromatid differentiation (SCD) in the same metaphase was observed in a human melanoma cell line after BrdU incorporation for 48-72 hr. This phenomenon was related to the time of BrdU incorporation by the cells: i.e., it was not observed after exposure to BrdU for only 17-20 hr. It is proposed, therefore, that the unusual staining pattern is caused through reduced BrdU incorporation by the cells after completing the first division.

Bromodeoxyuridine↗
PubMed1983

Cytogenetic testing of mutagenic and radioprotective effects of mesna.

The effects of mesna (sodium 2-mercaptoethane-sulfonate) on the frequency of sister chromatid exchange (SCE) and chromosomal aberrations were studied in PHA-stimulated lymphocytes in vitro. Our data give no evidence for either an increase of SCE or chromosomal aberrations and, thus, do not suggest a mutagenic or cancerogenic potential of this drug, when used clinically for the reduction of urotoxicity caused by oxazaphosphorine derivatives in cancer therapy. The possibility of a radioprotective effect of mesna could not be supported by the results obtained in this test system. However, there remained a slight comutagenic effect of mesna, if used together with irradiation, which should be taken into account when this drug is administered in the preparation of patients for bone marrow transplantation.

Chromosome Aberrations↗
PubMed1983

Nonrandom chromosome changes in malignant melanoma.

Chromosome aberrations were analyzed in 4 cases of malignant melanoma (MM) after disaggregation of the tumors with collagenase and short-term culture. In all cell cultures, the MM cells displayed a typical triangular spindle form. The chromosome number was near-diploid in one case and near-triploid in three cases. A total of 27 abnormal chromosomes were identified with the Giemsa banding technique. By far, the most common types of abnormalities were translocations, followed by deletions and isochromosomes. Chromosomes 1, 6, and 7 were found to be most frequently involved in structural aberrations. Markers originating from chromosomes 1 and 6 were found in all four cases, and abnormalities of chromosome 7 were found in three. Each marker chromosome was unique for a given case; no common markers for two or more cases were found. Based on the present results and an analysis of reports on the chromosomal constitution of MM cells in the literature, we suggest that abnormalities involving chromosomes 6 and 7 may be a characteristic feature of MM. Aberrations of chromosome 1, although common in MM, may be part of a general cytogenetic feature in human neoplasia.

Adult↗
PubMed1979

Demonstration of two different regions of lateral asymmetry in human Y chromosomes.

Two differently stained regions of lateral asymmetry were observed in the long arm of the human Y chromosome, following FPG staining. The first asymmetry was confined to band q12 of the long arm. The second asymmetrically stained region was located at the junction between bands q11 and q12. In the non-fluorescent Y chromosomes only one region of lateral asymmetry was found at the end of the long arm and its staining properties were similar to the region situated at the junction between q11 and q12 bands in the fluorescent Ys. The two morphologically distinguishable regions of lateral asymmetry are presumed to indicate sites containing different satellite DNAs in the human Y chromosome.

Humans↗
PubMed1978

Isolabeling of the long arm of the human Y chromosome demonstrated by the FPG technique.

Isolabeling segments were found in the distal region of the long arm of Y chromosomes derived from human leukocytes grown through two replication cycles in medium containing BrdU and stained by the FPG technique. Three main types of Y chromosome staining patterns were demonstrated: I-Y chromosome with typical SCD, II-Y chromosome with weakly stained distal regions of long arms (isolabeling segments), III-Y chromosome with both terminal regions displaying SCD interrupted by one isolabeled segment. The existence of different types of Y chromosome staining patterns was explained on the basis of the previously described hypothesis of unequal distribution of thymine residues between two DNA polynucleotide chains in the distal part of the long arms of human Y chromosomes.

Bisbenzimidazole↗
PubMed1978

Cytofluorimetric measurement of DNA content in the cells of the transplantable melanotic and amelanotic Bomirski melanoma in golden hamster (Mesocricetus auratus, Waterhouse).

Cytofluorimetric measurements of the DNA content in transplantable melanotic and amelanotic tumor cells were carried out. The mean content DNA is higher in the amelanotic cells. The DNA distribution patterns are different in both tumors: there is a distinct stem line of the cells in the melanotic tumors whereas in the amelanotic cells there is a great variability in the DNA content and the stem line of the cells is absent. The correlation between these findings and some biological properties of the melanotic and amelanotic tumors are discussed.

Animals↗